Plug for electric circuit



Aug- 3, 1948. w. 1 wlLsHusEN 2,446,317

PLUG FOR ELECTRIC CIRCUIT Filed March 27, 1945 f -Z I a L #J INVENTOR.

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Patented Aug. 3, 1948 UNI TE D SS TATgES T 0F FICE y 2,446,311: v

PLUG FOR ELECTRIC `CIRCUIT l y Wilmer L. Wilshusen, Garden City, Kans.

Application March 27, 1945, Serial No. 585,147

1 Claim. l

This invention relates to plugs for use in electric circuits and it is designed primarily for use in aircraft and in other places where the equipment is subjected to violent vibra-tion. It has been found in practice that where connector plugs are employed under these conditions, they work loose and gradually rotate with the result that the wires connected to the plug Jbecome broken. An object of the presen-t invention is to provide a connector -plug which is so constructed as to be held against rotation so that it will function properly even though subjected to constant vibration.

A further object is to provide a connector plug which can be readily secured to parts already in use.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claim, it being understood that changes may be made in the construction and arrangement of parts without departing from .the spirit of the invention as claimed.

In the accompanying drawing, the preferred form of the invention has been shown.

In said drawing;

Figure 1 is a side elevation of a connector plug constructed in accordance with the present invention, lthe same being shown positioned in a portion of an ordinary equipment case.

Figure 2 is a lsection on line 2-12 Fig. 1, the central stem being shown in plan.

Figure 3 is a face view of the retaining washer frming a. part of the device.

Figure 4 is a face view of the insulating block.

Figure 5 is a face view of a portion of the equipment case showing the opening provided therein for .the reception of the connector plug.

Figure 6 is a side view of .the outer or shell kportion of the plug.

Figure 7 is an end elevation thereof.

Figure 8 is a side elevation of the central stem of the plug, a portion being broken away.

Figure 9 lis a section on line 9-9 Figure 8.

Referring to the figures lby characters of reference, I designates a central stem which is cylindrical for the greater portion .of its length and is provided at one end with the usual ball 2. From the other end, however, projects a flattened extension 3, there being a shoulder 4 formed by the stem I at the base of the extension 3 and another shoulder 5 at the base of the ball 2.

That portion of the stem I between the shoulders 4 and 5 is cylindrical as before stated, and is tted snugly wi-thin an insulating sleeve 6 which, in turn, is surrounded by a shell 1. A washer 8 of insulating material is interposed between the shoulder 5 and the adjoining ends of sleeve 6 and shell 1.

The shell 'I is provided with a disk-like head 9 at that end thereof remote from washer 8 and adjacent to this head the shell is enlarged as shown at I0. This enlarged portion is screwthreaded as at I I, but the .threads are interrupted by one or more flat sides I2. A recess I3 is formed within the head 9 and is extended diametrically across the outer face thereof and this recess is proportioned to receive a block I4 of insulating material in which is formed .an angular opening I5. This opening is proportioned to receive the flattened extension 3 which, when positioned therein, will prevent the central stem I from rotating within the -shell 1 due to the fact that the engaged block I4 is held against rotation by .the Walls of the recess I3.

A retaining washer I6 is seated on the exten-V sion 3 and is held thereto by any suitable means, as by upsetting a portion ofthe extension so as to overlie a .portion of the washer, as indicated at I1. With the washer thus held to .the extension 3, the lblock I4, head 9, shell 1, sleeve 6 and stern I are all maintained fixed relative to each other.

The extension 3 can be provided with an integral pin I8 or the like at the end thereof to which a wire W can be joined as shown in Figures 1 and 2.

An opening I9 having one or more straight sides, is provided in the case of the equipment, a portion of which has been shown at 20. This opening is proportioned to receive the enlarged lportion lli of the shell 1 which will iit snugly therein and thus be held against rotation relative When this enlarged portionis thus between said nut and the head 9.

With the parts thus assembled it will be apparent that it becomes impossible for the connecting plug to rotate relative to the ease and, therefore, the possibility of the wire W becoming bent or twisted as a result of rotation due to vibration, is eliminated. Consequently, one of the hazards thus far experienced in the operation of airplanes, etc., is avoided.

What is claimed is:

The combination with a supporting structure having an opening provided with a straight wall, of a connecting plug including a stem having a shoulder at one end and a flattened extension at its other end, an insulating sleeve on the stem, an insulating block fitted snugly on and held against rotation by the flattened extension, a shell tted on the insulating sleeve having an enlarged end portion shaped to fit Within and to be held against rotation by the Walls of the opening in the supporting structure, a head integral with saidenlarg-ed end portion` ofv the shell, having a recess constituting a seat for the block,

relative rotation, said enlarged .portion having 4, enlarged portion and cooperating with the head to grip the supporting structure.

WILMER L. WILSHUSEN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS l0 Number f rName Y Date 800,755 McBerty Oct. 3, 1905 1,499,246 Oakes June 24, 1924 Yaxley Feb. 16, 1926 screw threads, and a nut engaging the threaded 15 

